1. Field of the Invention
The present invention relates to an ink jet printer head such as a piezoelectric ink jet printer head.
2. Discussion of Related Art
Japanese Patent Application Publication No. P2002-144590A or its corresponding U.S. Patent Application Publication No. US 2002/0024568A1 discloses an on-demand piezoelectric ink jet printer head which is essentially constituted by a head unit having a plurality of ink ejection nozzles arranged in a direction perpendicular to a printing direction in which a carriage is moved. The head unit includes (a) a cavity unit having the ink ejection nozzles, a plurality of pressure chambers communicating with the ink ejection nozzles, respectively, and a manifold chamber which supplies ink to each of the pressure chambers; (b) a piezoelectric actuator which is provided on a back or upper surface of the cavity unit and includes a plurality of active portions corresponding to the pressure chambers, respectively; and (c) a flexible flat cable which sends a plurality of electric signals to the piezoelectric actuator.
In the head unit disclosed by the above-indicated publications, the cavity unit is constituted by a plurality of thin sheet members which are stacked on each other and are bonded with adhesive to each other, and the piezoelectric actuator that is also of a sheet-member-stacked type is bonded with adhesive to the back or upper surface of the cavity unit. According to the above-indicated publications, a back or upper surface of the head unit is fixed to a support member mounted on the carriage, in such a manner that edge portions of the back or upper surface of the cavity unit of the head unit is bonded with adhesive to a bottom wall of a synthetic-resin-based head holder as the support member. An ink cartridge is detachably attached to an upper surface of the head holder.